Rush was traveling westbound on I-70, just east of the Taylorstown exit, when she left the passing lane and traveled 342 feet in the median before the vehicle rolled onto its roof, police said.

Dominic and his mother were thrown from the vehicle. Police said neither of them was wearing a seat belt and Crystal will likely be cited.

"There was a booster seat in the vehicle. The child was not using the booster seat and was not seat-belted inside the vehicle," Plume said. "Until the child is 8 years old, they're required to be in a booster seat and in it correctly. In this case, neither was the case. He wasn't seat-belted in, he wasn't using his booster seat properly. So there will probably be a citation issued at least for that if not other charges also."

Dominic was pinned under the vehicle. Witnesses lifted the SUV and removed him. The boy was pronounced dead at the scene.

"He liked to play. Anything that had to do with having fun, he was there -- swimming, fishing, whatever. He was active," Petrie said.

Crystal Rush was flown to Allegheny General Hospital and remained in serious condition Thursday morning.

Police continue to investigate the cause of the crash.

Photos: Boy, 6, killed in crash on Interstate 70

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6-year-old dies in Jeep crash

Police said Dominic Rush was a passenger in a rollover crash near the Taylorstown exit on Interstate 70 in Buffalo Township, Washington County.

ABSOLUTE MISERY. NOW YOU CAN CURE YOUR ALLERGIES FOR GOOD. . MANYTHING TO DO WITH HAVING FUN HE WAS THERE. HE WAS ACTIVE. SDP REMEMBERING A YOUNG BOY KILLED IN A DEADLY ACCIDENT. HIS MOTHER BEHIND BE WHEEL WHEN THE SUV CRASHED. THE CHILD IS IN THE HOSPITAL AND SHE IS FATSING CHARGES. ASHLI HARDWAY JOINS US LIVE TO EXPLAIN WHY. Reporter: CRYSTAL WAS AIR LIFTED HERE WHERE SHE REMAINS IN SERIOUS CONDITION. STATE POLICE SAY WHEN SHE GETS OUT SHE WILL LIKELY BE HEARING FROM THEM. THAT'S BECAUSE NEITHER SHE NOR HER SON HAD THEIR SEAT BELTS ON. IT WAS MY LITTLE BUDDY. I'M LIKE THIS DIDN'T BE HAPPENING. THAT'S WHAT I KEPT TELLING MYSELF. Reporter: LITTLE DOMINIC WAS RIDING IN HIS MORES JEEP CHEROKEE LAST NIGHT. FOR SOME REASON 23-YEAR-OLD CRYSTAL RUSH LEFT THE LEFT LANE. WHEN THE VEHICLE HIT THE CENTER MEDIAN IT FLIPPED SEVERAL TIMES. BOTH OCCUPANTS WERE EJECTED. Reporter: A PASSER BY SHOT THIS VIDEO THAT SHOWS THE LARGE EMERGENCY RESPONSE. WITNESSES SAID THE JEEP LANDED ON TOP OF DOMINIC AND PEOPLE LIFTED THE VEHICLE OFF OF THE BOY, BUT IT WAS TOO LATE. HE DIED THERE ON SCENE. INVESTIGATORS FOUND NEITHER HE NOR HIS MOTHER WERE BUCKLED IN. NOW THE BOY'S MOTHER WILL BE LOOKING AT A CITATION. IF YOU'RE A CHILD 8 YEARS OLD YOU'RE REQUIRED TO BE IN SOME TYPE OF SEAT. HE WENT SEAT BELTED IN OR USING HIS BOOSTER SEAT PROPERLY. THERE WILL BE A CITATION ISSUED, AT LEAST FOR THAT, IF NOT OTHER CHARGES ALSO. Reporter: THE DETAILS MEAN LITTLE TO FRIENDS OF DOMINIC WHO ARE JUST REMEMBERING THE SWEET LITTLE BOY NEXT DOOR. HE WAS ACTIVE. HE'D COME DOWN TO MY HOUSE ALL THE TIME. PL PLAYED Wii. PLAYED PLAYSTATION. HE LIKED TO PLAY. ANYTHING TO DO WITH HAVING FUN, HE WAS THERE. SWIMMING, FISHING, WHATEVER. HE WAS ACTIVE. Reporter: HE WAS IN KINDERGARTEN THROUGH FEBRUARY OF THIS YEAR. THE DISTRICT SUPERINTENDENT SAYS COUNSELORS WERE ON HAND TODAY FOR ANYONE WHO NEEDED THEM. SHE SAID THAT LETTERS WILL BE